TROY — Mayor Patrick Madden testified Thursday in front of a Rensselaer County grand jury scrutinizing the city's sale of a wooded lot in Lansingburgh to former City Engineer Andrew Donovan.

Madden went in front of the panel for about five minutes.

"I didn't know what to expect," Madden said after he left the third-floor grand jury room in the County Court House.

He declined to discuss his testimony. Though grand jury proceedings are held in secret, witnesses are allowed to speak after appearing about what they were asked and how they responded.

Two years ago, Madden signed off on the cancellation of a reverter clause that required Donovan to make improvements to property at 226 Cemetery Road in return for the city agreeing to sell the land to him for $3,500. After the reverter clause was canceled, Donovan listed the land for sale for $65,000.

The attorney general is investigating the land sale and subpoenaed personnel files, deeds and other records earlier this month. The state is scrutinizing Donovan's purchase of the land in 2015 and the city's decision the following year to cancel the reverter clause.

Reverter clauses are used to encourage buyers to make improvements on property.

At the time of his purchase, Donovan said he planned to build a home on the site. Donovan was the city's engineer at the time of the purchase, but had left the position by the time the land was listed for sale.

Madden was the second grand jury witness of the day. Earlier, City Assessor Sharon Martin went before the panel. Mary Nagy, who handles title searches in the city's corporation counsel office, went into the grand jury room after Madden finished his brief testimony. A state Attorney General's investigator testified after Nagy completed her testimony before the grand jury.

Republicans on the City Council filed a complaint with the attorney general's office in 2017 after the Times Union revealed the reverter clause had been lifted and Donovan was trying to sell the house.

The Attorney General's investigation has already led to the arrest of James E. Lance III, a code enforcement officer who was charged last year with felony counts of grand larceny as a public corruption crime, as well as corrupting the government, tampering with public records, offering a false instrument for filing, falsifying business records and defrauding the government.

He was also charged with official misconduct, a misdemeanor.

County officials confirmed this month that a subpoena dated Jan. 3 directed the county to turn over copies of the deed signed by former Mayor Lou Rosamilia in 2015 transferring the land to Donovan and the release signed in 2016 by Madden.

The city also was subpoenaed Jan. 3 to release documents including its policies on land sales and personnel records, Corporation Counsel James Caruso said at the time.

The grand jury is expected to resume hearing testimony Jan. 31 with members of the code enforcement office and other city officials expected to appear.