Investigators searching for 84-year-old Nancy Guthrie found a pair of black gloves near her Arizona home, which will be tested for DNA and may match footage of a person seen outside her house.

The FBI released a description of a male suspect, about 5’9”–5’10” with an average build, wearing a black 25-liter Ozark Trail Hiker Pack and a distinctive ski mask.

Authorities have been following thousands of tips since releasing surveillance footage showing the suspect tampering with a porch camera and carrying a possible weapon.

The family has received ransom notes demanding bitcoin, but no proof of life has been provided; multiple video appeals have been made for her safe return, CBS News has reported.

The FBI and local police continue extensive searches in the Tucson area and have offered a $50,000 reward for information leading to her location or the arrest of those responsible.