A last-minute twist that caught advocates by surprise is threatening to derail legislation to create new federal resources for those with autism and other developmental disabilities who are at risk of wandering.

The bill known as Kevin and Avonte’s Law would expand an existing program designed to help those with Alzheimer’s disease who are prone to bolting to include kids with developmental disabilities too.

The legislation, which was approved by the U.S. Senate in July, would authorize $2 million annually for the U.S. Department of Justice to issue grants to law enforcement agencies across the country to provide tracking devices, training and other resources to address wandering.

A markup was scheduled this week in the House Judiciary Committee but the hearing was abruptly postponed the morning it was set to take place.

Judiciary Committee aides initially blamed the postponement on a scheduling conflict, but later acknowledged that more may have been at play saying “we have worked with members to identify fixes to address the privacy concerns.”

The delay came after the conservative group Americans for Limited Government put out a statement opposing the bill suggesting that it would “allow for the attorney general to authorize tracking chips to be inserted involuntarily into people.”

Disability advocates who have long pushed for the legislation said that nothing could be further from the truth. The bill makes funding available for wearable tracking devices — no chips or anything that would be inserted — and it specifically forbids the use of such technology if an individual objects.

Families with children at risk of wandering could request the trackers from participating law enforcement agencies. Devices are not actively monitored, but can allow law enforcement to locate a child who is reported missing, advocates said.

“This program has already been in place for 20 years for people with Alzheimer’s and we’re just trying to get it opened up to people with developmental disabilities too,” said Lori McIlwain, chair of the National Autism Association and head of the Autism Safety Coalition, which is comprised of a dozen disability advocacy groups supporting the bill.

Roughly half of children with autism have wandered away from a safe place, research suggests. And according to the Autism Safety Coalition, over 100 people with autism or Down syndrome have died in eloping incidents since 2011 alone, with a new death reported just last week.

McIlwain cited an example of a family in Michigan whose child with autism perished after wandering away. The family subsequently sought a tracking device for their other child on the spectrum, but was told that a law enforcement program providing such technology in their community was limited to individuals ages 65 and up.

“This is a common-sense bill. It helps prevent deaths in our community and it helps law enforcement find people quicker,” she said. “There’s a lot of misinformation out there. We’re just trying to get people to read the bill.”

Judiciary Committee aides said no new hearing is currently scheduled.

McIlwain said she’s hopeful that the bill will bypass the Judiciary Committee and go directly to the House floor so that it can be considered in the little time remaining before the end of this Congress.