After months of keeping their hands off implementation of Colorado’s voter-approved initiative for recreational marijuana, the state’s political establishment may be having some second thoughts. Two bills filed late in the Colorado Legislature appear to be on a fast track to put the first real limits on recreational marijuana since voters passed Amendment 64 in 2012, making recreational pot sales since Jan. 1, 2014, legal for anyone age 21 or older. On Tuesday, Dr. Michael Distefano testified that Colorado Children’s Hospital has treated seven juveniles for acute illnesses stemming from ingesting edible forms of marijuana since the law went into effect. And, on Monday night, before Distefano appeared before the House Committee on Health, Insurance, and Environment on two bills to rein in recreational marijuana, a mother of three from Denver on the phone with a 911 operator about the hallucinations being experienced by her husband was killed when he shot her in the head. Dead is 44-year old Kristine A. Kirk. Her husband, Richard Kirk, 47, is being held without bond on a charge of first-degree murder. He volunteered his guilt while in custody, but before police began interrogating him. Denver Police are investigating whether Kirk smoked or ingested an edible form of marijuana. The 911 call was originally thought to be a domestic disturbance, and the dispatcher was told that the only gun in the home was kept in a safe. Officers arrived just ahead of the shooting. With just three weeks before its scheduled adjournment, such events appear to be pushing the Colorado Legislature to make changes to the state’s marijuana laws in at least two important areas. First, it appears to be ready to impose limits on the concentrations of marijuana. Amendment 64 permits Colorado residents to purchase one ounce of marijuana, but it makes no distinction between one ounce of just the leafy green plant or one ounce of a concentrated form such as the hash oil used in many edible forms of the drug. Second, lawmakers want to put more restrictions on the edible forms, including eliminating items that mimic popular cookies and candies and might appear good for marketing to children. Amendment 64 advocates insist there is no toxic level for marijuana, and they are expected to push back hard on the two bills that have little time to run all legislative hurdles and still make it to the governor’s desk this year. Without changes to the law, Colorado’s edible marijuana products are subject only to regulation by the Department of Revenue’s pot unit but not by public health officials, whose only role is to consult when asked. State Rep. Frank McNulty (R-Highlands Ranch) says that achieving equivalences between marijuana from plants with the concentrates used in edibles will probably cost the state at least $100,000 to implement, but that every passing day is giving lawmakers reasons why some tightening is necessary. The reports of edible marijuana making children sick and possibly playing a role in Kristine Kirk’s murder coincides with a new study showing that casual marijuana use can cause changes in the brain. Published in the Journal of Neuroscience, a 10-page report on the study says that brain alterations occur in young adults using marijuana before any dependence develops. The report’s author, Dr. Hans Breiter of Northwestern University’s Feinberg School of Medicine and Massachusetts General Hospital, said that longer-term studies are needed to see if brain changes cause any symptoms over time. Meanwhile, this year’s “4/20” event in Denver on April 19 and 20 won’t be a protest, but a festival at the Civic Center expected to draw 80,000 people each day. Organizers say they are spending $300,000 on the two-day event. Festival-goers will be warned that cannabis cannot be used in public, and police citations for public consumption are likely.